In a statically typed world, Ted tries to compile his project and gets an error saying, "last_name doesn't exist". In a dynamically typed world, Ted ships his code into production (or possibly testing) and gets a call at 4:00a.m. saying it threw an exception or just died. (The testers are in Bangladesh.)

In Alan Kay's world (or at least that of the author), the code goes on robustly producing whatever results it produces in the case where no one has a last name. Better?